/* strindex: return index of t in s, -1 if none. */
int strindex(char s[], char t[])
{
	int i, j, k;

	for(i = 0; s[i] != '\0'; i++){
		for (j = i, k = 0; t[k] != '\0' && s[j] == t[k]; j++, k++)
			;
		if (k > 0 && t[k] == '\0')
			return i;
	}

	return -1;
}